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Understanding which species will be extirpated in the aftermath of large-scale human disturbance is critical to mitigating biodiversity loss, particularly in hyperdiverse tropical biomes. Deforestation is the strongest driver of contemporary local extinctions in tropical forests but may occur at different tempos. The 2 most extensive tropical forest biomes in South America-the Atlantic Forest and the Amazon-have experienced historically divergent pathways of habitat loss and biodiversity decay, providing a unique case study to investigate rates of local species persistence on a single continent. We quantified medium- to large-bodied mammal species persistence across these biomes to elucidate how landscape configuration affects their persistence and associated ecological functions. We collected occurrence data for 617 assemblages of medium- to large-bodied mammal species (>1 kg) in the Atlantic Forest and the Amazon. Analyzing natural habitat cover based on satellite data (1985-2022), we employed descriptive statistics and generalized linear models (GLMs) to investigate ecospecies occurrence patterns in relation to habitat cover across the landscapes. The subregional erosion of Amazonian mammal assemblage diversity since the 1970s mirrors that observed since the colonial conquest of the Atlantic Forest, given that 52.8% of all Amazonian mammals are now on a similar trajectory. Four out of 5 large mammals in the Atlantic Forest were prone to extirpation, whereas 53% of Amazonian mammals were vulnerable to extirpation. Greater natural habitat cover increased the persistence likelihood of ecospecies in both biomes. These trends reflected a median local species loss 63.9% higher in the Atlantic Forest than in the Amazon, which appears to be moving toward a turning point of forest habitat loss and degradation. The contrasting trajectories of species persistence in the Amazon and Atlantic Forest domains underscore the importance of considering historical habitat loss pathways and regional biodiversity erosion in conservation strategies. By focusing on landscape configuration and identifying essential ecological functions associated with large vertebrate species, conservation planning and management practices can be better informed., (© 2024 Society for Conservation Biology.)

The Amazon forest has the highest biodiversity on Earth. However, information on Amazonian vertebrate diversity is still deficient and scattered across the published, peer-reviewed, and gray literature and in unpublished raw data. Camera traps are an effective non-invasive method of surveying vertebrates, applicable to different scales of time and space. In this study, we organized and standardized camera trap records from different Amazon regions to compile the most extensive data set of inventories of mammal, bird, and reptile species ever assembled for the area. The complete data set comprises 154,123 records of 317 species (185 birds, 119 mammals, and 13 reptiles) gathered from surveys from the Amazonian portion of eight countries (Brazil, Bolivia, Colombia, Ecuador, French Guiana, Peru, Suriname, and Venezuela). The most frequently recorded species per taxa were: mammals: Cuniculus paca (11,907 records); birds: Pauxi tuberosa (3713 records); and reptiles: Tupinambis teguixin (716 records). The information detailed in this data paper opens up opportunities for new ecological studies at different spatial and temporal scales, allowing for a more accurate evaluation of the effects of habitat loss, fragmentation, climate change, and other human-mediated defaunation processes in one of the most important and threatened tropical environments in the world. The data set is not copyright restricted; please cite this data paper when using its data in publications and we also request that researchers and educators inform us of how they are using these data., (© 2022 The Authors. Ecology published by Wiley Periodicals LLC on behalf of The Ecological Society of America.)

In a scenario where escalating human activities lead to several environmental changes and, consequently, affect mammal abundance and distribution, β-diversity may increase due to differences among sites. Using the ecological uniqueness approach, we analyzed β-diversity patterns of ground-dwelling mammal communities recorded through comprehensive camera trap monitoring within eight tropical forests protected areas in Mesoamerica and South America under variable landscape contexts. We aimed to investigate whether the contribution of single sites (LCBD) and single species (SCBD) to overall β-diversity could be explained by community metrics and environmental variables, and by species metrics and biological traits, respectively. Total β-diversity was also partitioned into species replacement and richness difference. We related LCBD to species richness, total relative abundance, functional indices, and environmental variables (tree basal area, protected area size, NDVI, and precipitation seasonality), and SCBD to species naïve occupancy, relative abundance, and morphoecological traits via beta regression. Our findings showed that LCBD was primarily explained by variation in species richness, rather than relative abundance and functional metrics. Protected area size and tree basal area were also important in explaining variation in LCBD. SCBD was strongly related to naïve occupancy and relative abundance, but not to biological traits, such as body mass, trophic energy level, activity cycle, and taxonomic category. Local β-diversity was a result of species replacements and to a lesser extent differences in species richness. Our approach was useful in examining and comparing the ecological uniqueness among different sites, revealing the regional scale current status of mammal diversity. High LCBD values comprised sites embedded within smaller habitat extents, hosting lower tree basal areas, and harboring low species richness. SCBD showed that relatively ubiquitous species that occur at variable abundances across sites contributed most to β-diversity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Neotropical mammal diversity is currently threatened by several chronic human-induced pressures. We compiled 1,029 contemporary mammal assemblages surveyed across the Neotropics to quantify the continental-scale extent and intensity of defaunation and understand their determinants based on environmental covariates. We calculated a local defaunation index for all assemblages-adjusted by a false-absence ratio-which was examined using structural equation models. We propose a hunting index based on socioenvironmental co-variables that either intensify or inhibit hunting, which we used as an additional predictor of defaunation. Mammal defaunation intensity across the Neotropics on average erased 56.5% of the local source fauna, with ungulates comprising the most ubiquitous losses. The extent of defaunation is widespread, but more incipient in hitherto relatively intact major biomes that are rapidly succumbing to encroaching deforestation frontiers. Assemblage-wide mammal body mass distribution was greatly reduced from a historical 95th-percentile of ~ 14 kg to only ~ 4 kg in modern assemblages. Defaunation and depletion of large-bodied species were primarily driven by hunting pressure and remaining habitat area. Our findings can inform guidelines to design transnational conservation policies to safeguard native vertebrates, and ensure that the "empty ecosystem" syndrome will be deterred from reaching much of the New World tropics.

Agricultural frontier expansion into the Amazon over the last four decades has created million hectares of fragmented forests. While many species undergo local extinctions within remaining forest patches, this may be compensated by native species from neighbouring open-habitat areas potentially invading these patches, particularly as forest habitats become increasingly degraded. Here, we examine the effects of habitat loss, fragmentation and degradation on small mammal assemblages in a southern Amazonian deforestation frontier, while accounting for species-specific degree of forest-dependency. We surveyed small mammals at three continuous forest sites and 19 forest patches of different sizes and degrees of isolation. We further sampled matrix habitats adjacent to forest patches, which allowed us to classify each species according to forest-dependency and generate a community-averaged forest-dependency index for each site. Based on 21,568 trap-nights, we recorded 970 small mammals representing 20 species: 12 forest-dependents, 5 matrix-tolerants and 3 open-habitat specialists. Across the gradient of forest patch size, small mammal assemblages failed to show the typical species-area relationship, but this relationship held true when either species abundance or composition was considered. Species composition was further mediated by community-averaged forest-dependency, so that smaller forest patches were occupied by a lower proportion of forest-dependent rodents and marsupials. Both species richness and abundance increased in less isolated fragments surrounded by structurally simplified matrix habitats (e.g. active or abandoned cattle pastures). While shorter distances between forest patches may favour small mammal abundances, forest area and matrix complexity dictated which species could persist within forest fragments according to their degree of forest-dependency. Small mammal local extinctions in small forest patches within Amazonian deforestation frontiers are therefore likely offset by the incursion of open-habitat species. To preclude the dominance of those species, and consequent losses of native species and associated ecosystem functions, management actions should limit or reduce areas dedicated to pasture, additionally maintaining more structurally complex matrix habitats across fragmented landscapes., Competing Interests: The authors have declared that no competing interests exist.

Mammals represent the largest-bodied elements of the world's surviving megafauna and provide several key ecosystems services, yet their populations are often under steep decline throughout the tropics. Anthropogenic defaunation is one the most important contemporary threats to modern mammal faunas. Although the Atlantic Forest biome of South America shows several clear signs of defaunation, the extent to which this biome has lost its mammal fauna remains poorly understood. Here, we collate and analyze a comprehensive body of secondary data to quantitatively assess the spatial patterns of defaunation of all medium- to large-bodied Atlantic Forest mammals which were then classed by morpho-ecological traits. We used a Defaunation Index, which was scaled-up to the entire biome using kriging interpolation, to examine the integrity of site-specific mammal faunas. We further use environmental and socioeconomic predictors to explain the drivers of defaunation. Our results show high levels of defaunation (>0.5) for most of the Atlantic Forest. Apex predators, other carnivores, large-bodied mammals and large herbivores were among the most defaunated functional groups. Remaining native vegetation cover, forest fragment size, and the largest neighboring forest remnant were the main negative predictors of defaunation. We conclude that medium- to large-bodied Atlantic Forest mammals are under high levels of threat due to historical population losses that continue today. A conservation action plan thus becomes imperative to prevent this biome from becoming an even "emptier forest", severely compromising patterns of diversity, ecological processes and ecosystem functioning., Competing Interests: The authors have declared that no competing interests exist.

Oil palm monoculture comprises one of the most financially attractive land-use options in tropical forests, but cropland suitability overlaps the distribution of many highly threatened vertebrate species. We investigated how forest mammals respond to a landscape mosaic, including mature oil palm plantations and primary forest patches in Eastern Amazonia. Using both line-transect censuses (LTC) and camera-trapping (CT), we quantified the general patterns of mammal community structure and attempted to identify both species life-history traits and the environmental and spatial covariates that govern species intolerance to oil palm monoculture. Considering mammal species richness, abundance, and species composition, oil palm plantations were consistently depauperate compared to the adjacent primary forest, but responses differed between functional groups. The degree of forest habitat dependency was a leading trait, determining compositional dissimilarities across habitats. Considering both the LTC and CT data, distance from the forest-plantation interface had a significant effect on mammal assemblages within each habitat type. Approximately 87% of all species detected within oil palm were never farther than 1300 m from the forest edge. Our study clearly reinforces the notion that conventional oil palm plantations are extremely hostile to native tropical forest biodiversity, which does not bode well given prospects for oil palm expansion in both aging and new Amazonian deforestation frontiers.

Human presence and activity in tropical forest is thought to exert top-down regulation over the various 'green-world' pathways of plant-based foodwebs. However, these effects have never been explored for the 'brown-world' pathways of fecal-detritus webs. The strong effects of humans on tropical game mammals are likely to indirectly influence fecal detritivores (including Scarabaeine dung beetles), with subsequent indirect impacts on detrivore-mediated and plant-facilitating detrital processes. Across a 380-km gradient of human influence in the western Brazilian Amazon, we conducted the first landscape-level assessment of human-induced cascade effects on the fecal detritus pathway, by coupling data on human impact, game mammal and detritivore community structure, and rate measurements of a key detritus process (i.e. dung beetle-mediated secondary seed dispersal). We found evidence that human impact indirectly influences both the diversity and biomass of fecal detritivores, but not detritivore-mediated processes. Cascade strength varied across detritivore groups defined by species' traits. We found smaller-bodied dung beetles were at higher risk of local decline in areas of human presence, and that body size was a better predictor of cascade structure than fecal resource manipulation strategy. Cascade strength was also stronger in upland, unflooded forests, than in seasonally flooded forests. Our results suggest that the impact of human activity in tropical forest on fecal-detritus food web structure is mediated by both species' traits and habitat type. Further research will be required to determine the conditions under which these cascade effects influence fecal-detritus web function.

Little information exists on mixed-species groups between primates and other mammals in Neotropical forests. In this paper, we describe three such associations observed during an extensive large-vertebrate survey in central Amazonia, Brazil. Mixed-species groups between a primate species and another mammal were observed on seven occasions between squirrel monkeys (Saimiri cf. ustus) and either South American coatis (Nasua nasua) or tayras (Eira barbara) and between brown capuchins (Cebus apella) and coatis. All associations were restricted to floodplain forest during its dry stage. We suggest that the associations involving the coatis are connected to foraging and vigilance but may be induced by a common alternative food resource at a time of food shortage.

Forest corridors are often considered the main instrument with which to offset the effects of habitat loss and fragmentation. Brazilian forestry legislation requires that all riparian zones on private landholdings be maintained as permanent reserves and sets fixed minimum widths of riparian forest buffers to be retained alongside rivers and perennial streams. We investigated the effects of corridor width and degradation status of 37 riparian forest sites (including 24 corridors connected to large source-forest patches, 8 unconnected forest corridors, and 5 control riparian zones embedded within continuous forest patches) on bird and mammal species richness in a hyper-fragmented forest landscape surrounding Alta Floresta, Mato Grosso, Brazil. We used point-count and track-sampling methodology, coupled with an intensive forest-quality assessment that combined satellite imagery and ground truthed data. Vertebrate use of corridors was highly species-specific, but broad trends emerged depending on species life histories and their sensitivity to disturbance. Narrow and/or highly disturbed riparian corridors retained only a depauperate vertebrate assemblage that was typical of deforested habitats, whereas wide, well-preserved corridors retained a nearly complete species assemblage. Restriction of livestock movement along riparian buffers and their exclusion from key areas alongside deforested streams would permit corridor regeneration and facilitate restoration of connectivity.

Few researchers have investigated the synergistic effects of tropical forest fragmentation and disturbance on species persistence and abundance. We examined effects of both forest-patch metrics and forest disturbance in determining richness and abundance of midsized to large-bodied mammal species in a highly fragmented Amazonian forest landscape. Twenty-one forest fragments, ranging from 2 to 14,480 ha, and two continuous forest sites were sampled based on sightings, tracks, line-transect censuses, armadillo burrow censuses, and camera trapping. Patch occupancy of 37 species recorded ranged from 4% to all forest sites surveyed. Forest fragment size was the strongest predictor of species persistence, explaining 90% of the variation in species richness. Information-theoretic analysis confirmed that fragment area was the most important explanatory variable for the overall species richness and abundance of mammal species, followed by surface fires, which affected the abundance of seven species. Large mammal species were typically absent from fragments <100 ha, whereas some ubiquitous species were favored by fragmentation, exhibiting hyperabundance in small patches. Our findings highlight the importance of large (>10,000 ha), relatively undisturbed forest patches to maximize persistence and maintain baseline abundances of Neotropical forest mammal species.

Biodiversity inventories provide critical information on the ecology of natural ecosystems and inform conservation planning at local to regional scales.Based on a systematic review, we compiled data on over 1000 mammal inventories conducted throughout the Neotropics – from Mexico to Argentina – to document the status of assemblage‐wide field mammalogy in the world's most biodiverse Tropical realm.We analysed data using descriptive statistics and a confusion matrix to understand the prevalence of species' pseudo‐absences, map overall patterns of survey density, and quantify any geographic sampling bias.Based on the 1028 site‐specific inventories published between 1983 and 2020, mean species richness of medium‐ to large‐bodied mammals was 11.9 (± 8.8 standard deviation). Local inventories were distributed across elevational gradients, and overall sampling effort and survey techniques employed were extremely variable. The best‐sampled regions were the Brazilian Atlantic Forest and Mesoamerica, but we identified nine large assemblage‐wide Wallacean shortfalls and a pseudo‐absence rate of 11% (± 4% standard deviation); geographic sampling bias was largely related to human population density, regardless of the assemblages' intactness presumably found in the undersampled wilderness regions of the Neotropics.We document the 40‐year legacy of mammal field surveys throughout the Neotropics, where several glaring knowledge shortfalls still persist. This calls for an audacious research agenda for future Neotropical mammal studies, which should target sampling in more remote areas, standardise sampling methodology, and provide high‐resolution data that can be used to fill current knowledge shortfalls. To do so, Latin American countries and the wider international community will need to commit greater personnel and financial resources to understanding biodiversity patterns and processes related to the Tropical vertebrate fauna. [ABSTRACT FROM AUTHOR]

1. New World bats are heavily affected by the biophysical setting shaped by elevation and latitude. This study seeks to understand the patterns of bat species diversity across elevational, latitudinal and vegetation height gradients throughout the Neotropics. 2. Systematically gathered putative and empirical data on bat species distribution across the entire Neotropics were examined using descriptive statistics, spatial interpolation of bat taxonomic, functional and phylogenetic diversity, generalized linear models, generalized linear mixed models and phylogenetic generalized least squares. 3. We uncoupled the effects of elevation, latitude and vegetation height to predict Neotropical bat diversity, showing that dietary level, home range and habitat breadth were the most important ecological traits determining coarse-scale bat distributions. Latitude was largely responsible for sorting the regional species pool, whereas elevation appears to apply an additional local filter to this regional pool wherever tropical mountains are present, thereby shaping the structure of montane assemblages. 4. Bats provide multiple ecosystem services and our results can help pinpoint priority areas for bat research and conservation across all Neotropics, elucidate the thresholds of species distributions, and highlight bat diversity hotspots at multiple scales. [ABSTRACT FROM AUTHOR]

Megadams are among the key modern drivers of habitat and biodiversity loss in emerging economies. The Balbina Hydroelectric Dam of Central Brazilian Amazonia inundated 312,900 ha of primary forests and created approximately 3500 variable‐sized islands that still harbor vertebrate populations after nearly 3 decades after isolation. We estimated the species richness, abundance, biomass, composition, and group size of medium‐ to large‐bodied forest vertebrates in response to patch, landscape, and habitat‐quality metrics across 37 islands and 3 continuous forest sites throughout the Balbina archipelago. We conducted 1168 km of diurnal censuses and had 12,420 camera‐trapping days along 81 transects with 207 camera stations. We determined the number of individuals (or groups) detected per 10 km walked and the number of independent photographs per 10 camera‐trapping days, respectively, for each species. We recorded 34 species, and patch area was the most significant predictor of vertebrate population relative abundance and aggregate biomass. The maximum group size of several group‐living species was consistently larger on large islands and in continuous patches than on small islands. Most vertebrate populations were extirpated after inundation. Remaining populations are unlikely to survive further ecological disruptions. If all vertebrate species were once widely distributed before inundation, we estimated that approximately 75% of all individual vertebrates were lost from all 3546 islands and 7.4% of the animals in all persisting insular populations are highly likely to be extirpated. Our results demonstrate that population abundance estimates should be factored into predictions of community disassembly on small islands to robustly predict biodiversity outcomes. Given the rapidly escalating hydropower infrastructure projects in developing counties, we suggest that faunal abundance and biomass estimates be considered in environmental impact assessments and large strictly protected reserves be established to minimize detrimental effects of dams on biodiversity. Conserving large tracts of continuous forests represents the most critical conservation measure to ensure that animal populations can persist at natural densities in Amazonian forests. Article impact statement: Tropical forest islands created by major hydroelectric dams can only retain very small, if any, vertebrate populations. [ABSTRACT FROM AUTHOR]

Maximizing cost-efficiency of biological surveys is of great importance to assess threats and monitor changes in tropical landscapes, particularly when survey costs are high as in Neotropical small mammals. Species detectability is mostly affected by local abundance but can further vary according to the forest size in fragmented landscapes. For example, species detection in smaller fragments may be higher due to either spatial constrains or forest vertical compression. Here, trade-offs between duration of trapping sessions and the cost of obtaining accurate small mammal individual and species data are investigated across a range of forest sizes, while accounting for potential sampling bias. Using a combination of live (Sherman and wire mesh) and pitfall traps, patterns of cumulative capture–recapture rates and community composition were examined across 16 night trapping sessions in 42 transects nested within 14 insular forest fragments of different sizes, and two continuous forest sites in the Central Brazilian Amazon. Based on 40,254 trap-nights, 604 captures were recorded from 22 identifiable species. Cumulative number of captures gradually increased along the entire trapping session, and on average, nearly half of all species required more than eight trapping nights to be detected at each sampling transect. Sampling bias was responsible for increased cumulative recapture rates in smaller fragments, but did not affect cumulative capture rates, or time to first detection of each species. Instead, time to first detection was mostly positively affected by species abundance. Our results highlight the higher effectiveness of long trapping sessions (i.e. > 10 nights) to detect uncommon species, increase sample sizes and recapture rates. Overall, if small mammal species abundance is high, sampling intensity can be reduced. However, regardless of species abundance, large fragments and continuous forest sites should be more intensively sampled to reduce any potential sampling bias. [ABSTRACT FROM AUTHOR]

Carnivores have long been used as model organisms to examine mechanisms that allow coexistence among ecologically similar species. Interactions between carnivores, including competition and predation, comprise important processes regulating local community structure and diversity. We use data from an intensive camera-trapping monitoring program across eight Neotropical forest sites to describe the patterns of spatiotemporal organization of a guild of five sympatric cat species: jaguar (Panthera onca), puma (Puma concolor), ocelot (Leopardus pardalis), jaguarundi (Herpailurus yagouaroundi) and margay (Leopardus wiedii). For the three largest cat species, we developed multi-stage occupancy models accounting for habitat characteristics (landscape complexity and prey availability) and models accounting for species interactions (occupancy estimates of potential competitor cat species). Patterns of habitat-use were best explained by prey availability, rather than habitat structure or species interactions, with no evidence of negative associations of jaguar on puma and ocelot occupancy or puma on ocelot occupancy. We further explore temporal activity patterns and overlap of all five felid species. We observed a moderate temporal overlap between jaguar, puma and ocelot, with differences in their activity peaks, whereas higher temporal partitioning was observed between jaguarundi and both ocelot and margay. Lastly, we conducted temporal overlap analysis and calculated species activity levels across study sites to explore if shifts in daily activity within species can be explained by varying levels of local competition pressure. Activity patterns of ocelots, jaguarundis and margays were similarly bimodal across sites, but pumas exhibited irregular activity patterns, most likely as a response to jaguar activity. Activity levels were similar among sites and observed differences were unrelated to competition or intraguild killing risk. Our study reveals apparent spatial and temporal partitioning for most of the species pairs analyzed, with prey abundance being more important than species interactions in governing the local occurrence and spatial distribution of Neotropical forest felids. [ABSTRACT FROM AUTHOR]

The advantages of mist-netting, the main technique used in Neotropical bat community studies to date, include logistical implementation, standardization and sampling representativeness. Nonetheless, study designs still have to deal with issues of detectability related to how different species behave and use the environment. Yet there is considerable sampling heterogeneity across available studies in the literature. Here, we approach the problem of sample size optimization. We evaluated the common sense hypothesis that the first six hours comprise the period of peak night activity for several species, thereby resulting in a representative sample for the whole night. To this end, we combined re-sampling techniques, species accumulation curves, threshold analysis, and community concordance of species compositional data, and applied them to datasets of three different Neotropical biomes (Amazonia, Atlantic Forest and Cerrado). We show that the strategy of restricting sampling to only six hours of the night frequently results in incomplete sampling representation of the entire bat community investigated. From a quantitative standpoint, results corroborated the existence of a major Sample Area effect in all datasets, although for the Amazonia dataset the six-hour strategy was significantly less species-rich after extrapolation, and for the Cerrado dataset it was more efficient. From the qualitative standpoint, however, results demonstrated that, for all three datasets, the identity of species that are effectively sampled will be inherently impacted by choices of sub-sampling schedule. We also propose an alternative six-hour sampling strategy (at the beginning and the end of a sample night) which performed better when resampling Amazonian and Atlantic Forest datasets on bat assemblages. Given the observed magnitude of our results, we propose that sample representativeness has to be carefully weighed against study objectives, and recommend that the trade-off between logistical constraints and additional sampling performance should be carefully evaluated. [ABSTRACT FROM AUTHOR]

Predicting the functional consequences of biodiversity loss in realistic, multitrophic communities remains a challenge. No existing biodiversity-ecosystem function study to date has simultaneously incorporated information on species traits, network topology, and extinction across multiple trophic levels, while all three factors are independently understood as critical drivers of post-extinction network structure and function. We fill this gap by comparing the functional consequences of simulated species loss both within (monotrophic) and across (bitrophic) trophic levels, in an ecological interaction network estimated from spatially explicit field data on tropical fecal detritus producer and consumers (mammals and dung beetles). We simulated trait-ordered beetle and mammal extinction separately (monotrophic extinction) and the coextinction of beetles following mammal loss (bitrophic extinction), according to network structure. We also compared the diversity effects of bitrophic extinction models using a standard monotrophic function (the daily production or consumption of fecal detritus) and a unique bitrophic functional metric (the proportion of daily detritus production that is consumed). We found similar mono- and bitrophic diversity effects, regardless of which species traits were used to drive extinctions, yet divergent predictions when different measures of function were used. The inclusion of information on network structure had little apparent effect on the qualitative relationship between diversity and function. These results contribute to our growing understanding of the functional consequences of biodiversity from real systems and underscore the importance of species traits and realistic functional metrics to assessments of the ecosystem impacts of network degradation through species loss. [ABSTRACT FROM AUTHOR]

Hydropower projects are rapidly expanding across lowland Amazonia, driving the conversion of large tracts of once-continuous forests into archipelagos embedded within a vast open-water matrix. Forest vertebrate populations thus become stranded in habitat islands, with their persistence governed by a combination of species life-history traits, habitat patch, and landscape context. We investigate the patterns of species extinction of 34 arboreal and terrestrial vertebrate species within three continuous forest sites and 37 land-bridge islands within one of the largest South American hydroelectric reservoirs, based on a combination of camera trapping, line-transect censuses, sign surveys, and armadillo burrow counts. Forest area was the best predictor of species persistence, so we classified all species into three levels of vulnerability to habitat insularization, with most species defined as ‘area-sensitive’. However, island occupancy was decisively determined by individual species traits, with wide-ranging species and poor dispersers showing high local extinction rates. We detected higher island occupancy rates of large vertebrate species compared to other Neotropical fragmented forest landscapes, suggesting that this is critically attributed to the absence of hunting pressure at Balbina. Nevertheless, most terrestrial and arboreal species have been driven to local extinction within the vast majority of islands, which have been largely defaunated. We predicted species composition across all 3546 islands within the reservoir, indicating that only ⩽2% of all islands continue to harbour at least 75% of all species. To minimise loss of vertebrate diversity, future hydroelectric dam projects in lowland tropical forests, if unavoidable, should consider their geographic location and landscape structure to maximise both island size and landscape connectivity, and set aside strictly protected reserves within reservoir areas. [ABSTRACT FROM AUTHOR]

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The occupancy probability of 35 large-bodied bird and mammal species was examined in relation to patch- and landscape-scale habitat and disturbance variables in 147 forest patches distributed throughout the Mexican Yucatán Peninsula. Occupancy was assessed on the basis of interviews with local informants. The most important predictors of vertebrate species richness, composition, and patch occupancy were human population density and the extent and quality of forest cover. Most forest species responded positively to forest extent, while felids in particular were sensitive to human population density. However, the effects of human density on patch occupancy operated at extremely local scales. Effects were stronger at a smaller grain size, offering optimistic prospects for conservation strategies that incorporate human population effects. Three arboreal frugivores (Ateles geoffroyi, Alouatta pigra, and Ramphastos sulfuratus) were strongly associated with total basal area of trees bearing fleshy fruits. The degree of hunting pressure was not related to human population density, and affected the occupancy probability of three game species, two of which (Mazama spp., Crax rubra) are among the most preferred prey across the Yucatán Peninsula. Levels of patch occupancy across this region varied considerably among species, and were best explained by body size and degree of forest habitat specificity, large-bodied species and habitat specialists being the most vulnerable. This study provides a quantitative assessment of the conservation potential of large vertebrates in Mesoamerica and identifies disturbance-sensitive species. This can inform regional-scale conservation planning at a time when low deforestation in parts of the Yucatán Peninsula still provides a narrow window of conservation opportunity given the rapid human population growth. [Copyright &y& Elsevier]

• Mammals and the ecosystem services (ESs) they provide are threatened worldwide. • We simulated defaunation to understand the impacts on ecosystem services. • Cumulative local extinctions will likely result in an overwhelming depletion of ESs. • Mammal functional redundancy buffered the ES erosion resulting from defaunation. • Human well-being depend on conservation planning to ensure mammals persistence. Mammals embody the apex of ecosystems processes, and their majestic diversity is overwhelmingly threatened in the Neotropical realm. Mammal population declines erode not only several levels of biological diversity, but may also impoverish critical ecosystem services (ES). Based on 2,427 putative baseline mammal assemblages derived from IUCN ranges polygons, we sought to understand, for the first time, the effects of mammal defaunation on natural ecosystem services throughout the entire Neotropical realm. At the assemblage-level, we simulated both stochastic and deterministic regimes of mammal defaunation, examining both diversity indices and classic metrics of ecological networks (e.g. modularity and nestedness). Our results show that ES losses are induced by declines in both taxonomic and functional diversity. Given any defaunation regime, Neotropical provinces undergo levels of ES erosion typically reaching less than a third of all potential network links. Geographic patterns of lost ecosystem services—resulting from simulated and real-world mammal extinctions—indicate that this will detrimentally affect human livelihoods across all major Neotropical provinces. We conclude that the ongoing defaunation process will promote irreversible failures of several mammal-mediated ecosystem processes at varying timescales. [ABSTRACT FROM AUTHOR]

Habitat loss and fragmentation are widely acknowledged to affect species diversity. However, the pathways through which their effects are propagated through foodwebs, ultimately driving species diversity, are less well understood. We investigated to what extent the effects of habitat loss and fragmentation on small mammals in Central Amazonia are mediated by higher trophic levels, specifically mammal mesopredators and apex predators. We surveyed these three mammal groups across 25 islands surrounded by a landscape-scale gradient of forest cover within the Balbina Hydroelectric Reservoir, in addition to three adjacent continuous forest sites. We then applied Structural Equation Modelling based on apex-predator incidence and either the abundance or biomass of mesopredators and small mammals. Apex-predator incidence was positively affected by landscape forest cover, as well as mesopredators abundance and biomass. Small mammal abundance, but not biomass, was negatively affected by forest cover. Contrary to expectations, the negative effect of forest cover on small mammal abundance was not mediated by a decrease in mesopredator abundance nor incidence of apex-predators. Instead, small mammal increase is apparently favoured by the proliferation of the few persisting smaller-bodied species which can take advantage of augmented resources related to habitat degradation. The further increment in small mammal abundance in the absence or lower abundance of predators might be prevented by the resource availability characterising these evergreen forests. Mammal assemblages seem to be primarily regulated by bottom-up forces. While this suggests a delayed extinction debt in Amazonian forest islands, remaining biodiversity might be poorly resilient to additional habitat disturbances. • We investigated whether fragmentation effects on small mammals are mediated by their predators. • Apex and mesopredators populations were negatively affected by fragmentation. • Small mammal abundance responded positively to fragmentation. • However, fragmentation effects on small mammals were not mediated by predators. • Bottom-up forces likely play a role controlling these mammal communities. [ABSTRACT FROM AUTHOR]

The Amazon is one of the most diverse biomes around the globe, currently threatened by economic and industrial development and climate change. Large mammals are keystone species, playing an important role in ecosystem structure and function as ecological engineers, while being highly susceptible to deforestation, habitat degradation, and human exploitation. Using a unifying hierarchical Bayesian spatial approach, we examine the site-use patterns of four large Amazonian Forest mammals and their relationships to anthropogenic factors at a biome-wide scale. Our results showed that species' patterns of site use are correlated with human induced habitat changes, and that this correlation is species-specific. The white-lipped peccary shows highest site-use estimates within strict protected areas, affected by proximity to urban areas and benefiting from indigenous territories, the tapir responding slightly to proximity to burned forested areas, while the giant armadillo and the jaguar were primarily affected by vegetation cover loss; disturbances related to the colonization of the Amazon. Our findings contribute to the understanding of how human-induced environmental changes influence the site-use patterns of these four large mammals, and inform future conservation and land use planning. Transboundary conservation efforts, empowering and integrating native (indigenous and non-indigenous) communities in land governance schemes, involving the private sector and securing the commitment of developed countries are important paths for the protection and sustainability of the globally-crucial Amazon rainforest. [ABSTRACT FROM AUTHOR]

• The quintessential plant of the Brazilian highlands — Araucaria (pinhão) — is paramount to vertebrates. • Pinhão exhibit low temporal redundancy, low consumer specificity, high reliability and abundance. • Araucaria behave as a keystone plant resource in the subtropical Atlantic Forest. Ecological attributes enable the identification of Keystone Plant Resources (KPRs), including their community-wide contribution to vertebrate consumers, which are often highly threatened in terrestrial ecosystems. KPRs have been defined by intersecting four ecological attributes that influence local communities of vertebrate frugivores: temporal redundancy (TR); degree of consumer specificity (CS); reliability (RR); and resource abundance (RA). The conifer Araucaria angustifolia (Bert.) O. Kuntze (Araucaria) is the main arborescent component of Araucaria Forests, within the subtropical Atlantic Forest of South America. The large Araucaria seeds (pinhão) are heavily consumed by local faunas, and consequently could be automatically defined as a KPR. However, no previous studies have conceptually assessed the pinhão as a KPR based on their ecological attributes and trophic interactions with vertebrates. Using empirical data and a comprehensive literature review, we examine the degree to which Araucaria trees can be formally defined as a KPR within the subtropical Atlantic Forest. Our results show for the first time that Araucaria is a KPR according to both its ecological attributes and community-wide importance. Araucaria cones exhibited low temporal redundancy, low consumer specificity, high resource reliability and high resource abundance, structuring the associated vertebrate consumers spatiotemporally. Our insights contribute to understanding the implications of historical Araucaria population declines through logging and deforestation, as well as ongoing vertebrate defaunation. Both of these processes can lead to changes in baseline ecological process (e.g. seed dispersal versus seed predation), forest regeneration, community reassembly, and potential evolutionary consequences such as seed downsizing. [ABSTRACT FROM AUTHOR]